Gender of offspring and risk of ovarian cancer: The HOPE study
To examine the association between gender of offspring and epithelial ovarian cancer (EOC). We compared gender of offspring between 664 incident EOC cases and 1531 controls participating in a population-based study conducted in Pennsylvania, Ohio, and New York from 2003-2008. Multivariable unconditional logistic regression was used to calculate odds ratios (ORs) and 95 % confidence intervals (CIs) adjusting for potential confounders. Bearing a male offspring was associated with an 8 % lower EOC risk; bearing all boys was associated with an 11 % lower risk. Compared to bearing all girls, bearing all boys was associated with a 14 % decrease risk. Increasing number of male offspring increased the protective effect (adjusted-OR: 0.92, 0.91, 0.84, for 1, 2, and 3+ boys compared to all girls). Results where similar when limiting cases to invasive disease and to the high-grade serous histotype. Fetal sex, which influences maternal hormonal milieu, may impact EOC risk.